Paper Details

Abstract

Phalaris minor Retz. is one of the most devastating weeds in wheat-based agroecosystems in South Asia, which has developed a significant resistance to the popular herbicides, resulting in massive losses in crop production. To be able to develop sustainable management strategies, it is necessary to understand the physiological and biochemical background of its adaptive variability. This research compared the morphological and biochemical diversity of P. minor populations collected in 6 major wheat-growing regions in Punjab, Pakistan, in herbicide-treated and untreated conditions. Significant regional variations were found in the plant height, leaf area, tiller production, plant density, and fresh biomass, with the Sargodha and D.G. Khan populations exhibiting superior growth and tolerance, and the Noorpur and Sialkot populations being relatively vulnerable. Biochemical profiling showed that the protease activity, total oxidant status, ascorbic acid, reducing sugars, and α-amylase activities showed wide differences in response to herbicide stress, which were indicated by different oxidative and metabolic adaptations. The potential biochemical defense mechanisms and adaptive resilience were sampled by high antioxidant and enzyme activities of the populations. These results offer biomarker and phenotypic data that the regional climatic conditions affect the progression of herb resistance in P. minor, and highlight the necessity of managing weeds in a climate-conscious way. Combining these morphological and biochemical characteristics offers a phenotypic model for determining herbicide-tolerant biotypes and making assumptions about genetic diversity in regional populations. The variability observed indicates the evolutionary selection pressure that causes the development of resistance in P. minor and the significance of using the traits as the initial resistance markers. This study forms a good basis for phenotypic and biochemical diversity to molecular characterization, which can be used in resistance surveillance, genetic differentiation investigations, and the development of region-specific weed management plans to reduce losses in wheat production. Keywords: Phalaris minor, herbicide resistance, morphological variation, biochemical markers, genetic diversity, Climate adaptation

To Cite This Article